Bits and bytes
A computer thinks in terms of binary digits. These digits are called bits and can have only two values: 0 or 1, which represent on or off in electrical terms. Bits are very small and have limited usefulness on their own outside of using them for true/false flags. They are grouped together into groups of 4, 8, 16, 32, or 64 to form data that a computer can use.
A byte in computer terms is a group of 8 bits. If we think in terms of a byte, the number 42 is represented like this, where the least significant bit is to the right and the most significant bit is to the left:
Figure 15.1: The number 42 represented in bits
The top row in Figure 15.1 shows the value, on or off, of each bit for an 8-bit byte that equals the number 42. The second row shows you the value represented by each bit in the byte. We can see that for the number 42, the bits for the values of 32, 8, and 2 are set. We can then add up those values and see that they equal 42: 32+8+2 = 42....
